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Climate shenanigans at the ends of the Earth: why has sea ice gone haywire?
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There is no doubt that 2016 has been a record-breaking year for Earth’s climate.
We will have to wait another couple of months for the final tally, but 2016 will be the hottest year in recorded history globally. Average temperatures are well above 1℃ warmer than a century ago.
Global average temperatures, and “global warming”, often give the impression of a gradual change in Earth’s climate occurring uniformly across the planet. This is far from the truth – particularly at the ends of the Earth. The Arctic and Antarctic are behaving very differently from the global picture.
One particular polar change that has caught the attention of scientists and the media this year has been the state of sea ice. The seasonal growth and decay of sea ice over the Arctic and Southern oceans is one of the most visible changes on Earth.
But in the past few months its seasonal progression has stalled, plunging Earth’s sea ice cover off the charts to the lowest levels on record for November. Explaining what has caused this unexpectedly dramatic downturn in sea ice is a tale of two poles.
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The northern polar region is an epicentre for change in our warming world.
On average, the Arctic is warming at around twice the global average rate. This is due to several environmental processes in the Arctic that amplify the warming caused by rising atmospheric greenhouse gas levels.
One of these amplifiers is the sea ice itself.
As the climate warms, it’s no surprise that ice melts. What is less obvious is that when bright, white ice melts it is replaced with a dark surface (the ocean or land). Just as a black car parked in the sun will warm up faster than a white one, so the dark surface absorbs more heat from the sun than ice. This extra heat promotes more ice loss, and so the cycle goes.
This can explain the marked long-term decline of Arctic sea ice. But it can’t explain why the past month has seen such a sudden and dramatic change. For this we need to look to the weather.
Arctic climate is characterised by very large natural swings – so much so that in the past few weeks some regions of the Arctic have been a whopping 20℃ warmer than expected for this time of year.
The polar regions are separated from milder equatorial climates by a belt of westerly winds. In the northern hemisphere these winds are commonly referred to as the jet stream.
The strength of the jet stream is related to the north-to-south (cold-to-warm) gradient in northern hemisphere climate. The amplification of warming in the Arctic has reduced this gradient, and some scientists believe that this is allowing the northern jet stream to develop a more meandering path as it travels around the globe.
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A weaving jet stream allows warm air to penetrate further northwards over the Arctic (the flip side is that extremely cold polar air can also be pulled south over the northern hemisphere continents, causing extreme cold snaps). This appears to be responsible for the current extremely warm temperatures over the Arctic Ocean, which have caused the normal advance of winter sea ice to stall.
In effect, what we are seeing in the Arctic is the combined effect of long-term climate change and an extreme short-term weather event (which itself is probably becoming more common because of climate change).
The southern storyIt’s a different story when we look at the ocean-dominated southern hemisphere.
Antarctic climate records point to a delay in some of the effects of “global warming”. The reasons are still debated, partly because of the much shorter climate records that scientists have to work with in the Antarctic.
But it is likely that the expansive Southern Ocean is an important climate change dampener that is able to “hide” some of the extra heat being absorbed by our planet beneath the ocean surface where we don’t feel it – yet.
Unlike the dramatic declines in Arctic sea ice over recent decades, the sea ice that surrounds Antarctica has been increasing slightly over the past three-and-a-half decades and 2014 set records for the most extensive Antarctic sea ice on record. So the decline in Antarctic sea ice since August this year to record low levels has come as somewhat of a surprise.
Again, the weather may hold part of the answer.
The westerly winds that circle the Southern Ocean (analogous to the northern hemisphere’s jet stream) have strengthened and moved closer to Antarctica over the past few decades. One of the effects of this has been to push sea ice away from the Antarctic continent, making for a more expansive coverage across the surrounding ocean.
But the westerly winds are fickle. They are able to change their path across the Southern Ocean very quickly. And so while the southward march in their average position over many years is clear, predicting their behaviour from month to month remains difficult. This spring the westerly winds have tended to sit closer to Australia and out of reach of Antarctica’s sea ice.
What Antarctica’s sea ice will do in the future is still an open question. Climate models indicate that Antarctica won’t remain protected from global warming forever, but just if and when this might cause Antarctica’s sea ice to replicate the Arctic sea ice loss is still anyone’s guess.
Lessons in the madnessExtreme years, such as 2016, are important as they provide glimpses of what the new normal of our climate system may look like in the not-too-distant future.
But these pointers to where we are going also need to be assessed in terms of where we have come from. For sea ice, logbooks from the age of heroic exploration suggest that the Antarctic system is mostly still operating within its normal bounds.
The same cannot be said for the Arctic. The decline of sea ice there has been likened to a ball bouncing down a bumpy hill – some years it will bounce higher than others, but eventually the ball will reach the bottom.
When it does, the Arctic Ocean will be ice-free in summer. That’s a boon for shipping, but don’t expect to see any polar bears on those Arctic cruises.
![The Conversation](https://counter.theconversation.edu.au/content/69485/count.gif)
Nerilie Abram receives funding from the Australian Research Council.
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Voters near proposed Adani mine oppose public loan for rail line, poll finds
Two-thirds of those polled in the state seat of Dalrymple think the government should not lend to the Indian mining giant
Two-thirds of voters in the Queensland region that would host Adani’s Carmichael mine think the miner should not be eligible for commonwealth funding, according a new poll.
The ReachTel poll of 544 voters in the state seat of Dalrymple found 66% were against the idea of “an Indian mining company worth over $12bn being eligible for this taxpayer funding towards their Galilee Basin project”.
How to reduce your kitchen's impact on global warming
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The food we eat is responsible for almost a third of our global carbon footprint. In research recently published in the Journal of Cleaner Production we ranked fresh foods based on how much greenhouse gas is produced from farm to fork.
Perhaps unsurprisingly, we found that red meat is the most emissions-intensive food we consume. But we also found that field-grown vegetables produce the least greenhouse gas. For instance, it takes about 50 onions to produce a kilogram of greenhouse gas, but only 44 grams of beef to produce the same amount.
We hope that chefs, caterers and everyday foodies will use this information to cook meals without cooking the planet.
From farm to forkTo produce our ranking, we compiled 369 published life-cycle assessment studies of 168 varieties of fresh produce, including fresh vegetables, fresh fruits, grains and nuts, dairy and livestock.
To find out how much greenhouse gas is produced in food production, we need to look at all the activities that produce emissions on the way from paddock to the regional distribution centre.
This includes: farm inputs from chemicals and fertilisers; fuel and energy inputs from irrigation and machinery for cultivation, harvesting and processing; and transport and refrigeration to the regional distribution centre.
It also includes emissions released from fertilised soils, plants and animals in fields, but doesn’t include activities such as retail, cooking in the home and human consumption.
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In the case of non-ruminant (chicken and pork) and ruminant (lamb and beef) livestock, processes covered include breeding, feed production, fertiliser use, farm/broiler energy use including heating, as well as transport, processing at the slaughterhouse and refrigeration to the regional distribution centre.
For lamb and beef the main source of emissions is methane. This is due to the fermentation process in which bacteria convert feed into energy in the animals’ stomachs. Methane can contribute anything above 50% of the total for ruminant livestock.
In the case of fish, species caught offshore by longline fishing fleets and trawlers have higher values because of the significantly higher fuel consumption than coastal fishing fleets.
It is difficult to compare different life-cycle analyses as these are unique to a particular growing region, farming practice, or methodological calculation. We agree there is danger in comparing one analysis with another to make direct comparisons and concrete conclusions.
However, after comparing 1,800 life-cycle analysis results, we feel far more comfortable in generalising the findings.
There is a large variation (median values) in results between food categories and also within categories, as illustrated below:
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Due to different culinary and dietary requirements, it is hard to argue that you can replace beef with onions. However, it is possible to substitute red meat with other meats, or plant-based protein sources, such as lentils and nuts, that have a lower impact.
Our study can help everyday citizens gain a better appreciation of the life-cycle impacts associated with the growing, harvesting and processing of food. With this knowledge, they can better plan, shop, prepare and cook food while reducing their carbon footprint.
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As the world grapples with the estimated US$940 billion per year in economic losses globally as a result of food loss and waste, these data illustrate the embedded carbon impacts when food is wasted in the supply chain.
Our results could be used to plan menus for individuals and catering companies who want to reduce their carbon footprint, by selecting foods from different categories.
Limited studies are available, however, for many popular foods. This includes tree nuts such as almonds and cashews, and quinoa, duck, rabbit, turkey and kangaroo.
We need to know more about the emissions intensity of these foods as they are often presented as alternative protein sources with low emissions. The lack of published data makes emissions intensity of these foods harder to validate, and such information is critical if attempts are made to inform dietary choice for environmental purposes.
![The Conversation](https://counter.theconversation.edu.au/content/68484/count.gif)
Karli Verghese undertakes research projects on a variety of food related, packaging, waste and life cycle assessment studies that have been and are funded by the commercial sector, government grants and competitive grants.
Stephen Clune previously worked for the Centre for Design at RMIT on a variety of food related research projects. Which were funded by the commercial sector, and competitive grants.
Ten years of backflips over emissions trading leave climate policy in the lurch
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Ten years ago on Saturday (December 10) Prime Minister John Howard announced the Coalition government would investigate an emissions trading scheme to reduce greenhouse gas emissions.
It was a remarkable backflip after a decade of rejecting such a policy. But fast-forward ten years and we have seen a dizzying array of U-turns on climate, most of them bad news for the atmosphere.
In the latest turn of events, the Coalition government has ruled out an emissions intensity scheme (a form of carbon trading) ahead of a national review of climate policy.
So as Australia gears up to review both its electricity market, with an initial report to be released on Friday, and climate policies, what might the future hold?
Howard’s slow warmingEmissions trading and carbon taxes were considered as far back as the very early 1990s.
In August 2000 an emissions trading proposal from the Australian Greenhouse Office fell in Cabinet, a result ascribed by journalists to then-Senator Nick Minchin. A second proposal, in July 2003 from at least five ministers, was personally vetoed by John Howard.
However, the pressure became overwhelming as the Millennium Drought wore on and states proposed to knit together a national scheme from below. Federal bureaucrats forced Howard’s hand. In Triumph and Demise, journalist Paul Kelly describes the moment Howard realised he would need to consider emissions trading:
[Department of Prime Minister and Cabinet secretary Peter] Shergold reached the bullet point advocating an ETS [Emissions Trading Scheme], Howard asked: “What’s that doing there?” It was the decisive moment; the next exchange was a classic in the advisory art.
[Treasury secretary Ken] Henry said: “Prime Minister, I’m taking as my starting point that during your prime ministership you will want to commit us to a cap on national emissions. If my view on that is wrong, there is really nothing more I can say.” It was a threshold moment.
“Yes, that’s right,” Howard said cautiously. Henry continued: “If you want a cap on emissions then it stands to reason that you want the most cost-effective way of doing that. That brings us to emissions trading, unless you want a tax on carbon.”
Howard did not want a tax on carbon.
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Kelly goes on to describe the shift in the business community as a “tipping point”.
So, on December 10 2006, John Howard put out a press release declaring that Peter Shergold and a panel would investigate an ETS. Shergold delivered his report in May 2007, and both the Coalition and Labor went to the 2007 election with an ETS policy.
Rudd’s great backflipKevin Rudd began auspiciously, receiving a standing ovation for ratifying the Kyoto Protocol, and famously declaring that:
climate change represents one of the greatest moral, economic and environmental challenges of our age.
But then Rudd and his inner circle began the tortuous process of formulating their own Carbon Pricing Reduction Scheme.
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It quickly became bogged down in concessions to the mining and electricity sectors. The first attempt at legislation, in May 2009, had a higher emissions reduction target of up to 25% if international action materialised, but failed.
The second effort created an even more generous cushion for the miners (doubled to A$1.5 billion) , but also failed after the Liberals replaced Turnbull with Tony Abbott on December 1, and the Greens in the Senate refused to vote for the plan.
Fresh from the horror of the Copenhagen climate conference, Rudd could have triggered a double-dissolution election over the scheme, but didn’t. A Greens proposal for an interim carbon tax was ignored. Rudd toyed with a behaviour change package, but was overruled.
On April 27 2010, Lenore Taylor broke the story that Rudd was kicking an ETS into the long grass for at least three years. Rudd’s approval ratings plummeted.
The toxic taxAfter Julia Gillard replaced Rudd in 2010, she negotiated a three-year fixed carbon price as part of an emissions trading scheme. It was quickly politicised as a “great big tax on everything”, and lasted two years after coming into effect.
Abbott proposed a different way of reaching the same emissions reduction target – a Direct Action scheme, which critics said simply subsidised polluters. Turnbull famously called it “bullshit” in 2009.
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Turnbull didn’t change Abbott’s policy when he became prime minister in September 2015. It has been recently reported that the Direct Action scheme’s Emissions Reductions Fund is “running out of steam”.
What next?Only the brave or ignorant would make any specific predictions about the absurd(ist) rollercoaster that is Australian climate change policy.
In the last few months we’ve seen the Climate Change Authority issue a majority and minority report.
On Tuesday, transmission companies called for a trading scheme at least for the electricity sector, but the right wing of Turnbull’s own party seems implacably opposed, as do commentators such as Andrew Bolt. Now the Turnbull government appears to have capitulated.
Business, industry and green groups have been crying out for policy consistency and an orderly transition away from coal.
Now we wait for the results of the two reviews into Australia’s electricity and climate policy.
There’s the Finkel Review into the reliability and stability of the National Electricity Market, which was commissioned in response to the South Australian blackout of September 28. That will presumably create new terrain in the debate on renewable energy for which there is currently no additional target beyond 2020.
Then there’s the review of Direct Action itself, and its safeguard mechanism. In 2015, under pressure from Nick Xenophon, the government promised it would begin the review on “30 June 2017, and complete it within five months”.
Meanwhile, the Labor Party will have to come up with its own specifics for how it would hit the Paris targets. It’s hard to see the Liberal and National parties changing their minds on this issue, having somewhat painted themselves into a corner (it was not always so).
Ten years ago, after successfully fending off action, John Howard finally had to do a U-turn, but it was too little too late. The pressures are now building again. It will be interesting to see if Labor is capable of capitalising on them, and if social movements are more able than they were to keep Labor to its rhetoric this time around.
Ten years from now, will we be charting another ten tempestuous and wasted years?
![The Conversation](https://counter.theconversation.edu.au/content/69641/count.gif)
Marc Hudson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.
Conservationists declare victory for wildlife as EU saves nature directives
EU president abandons plan to overhaul flagship birds and habitats directives following a huge public campaign
The European commission president, Jean-Claude Juncker, has been forced to abandon an overhaul of flagship nature laws after an unprecedented campaign that mobilised over half a million people in protest.
The popular birds and habitats directives protect almost a fifth of Europe’s landmass, about 200 wetlands, meadows and marine habitats, and more than a thousand animal and plant species.
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